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 (Fe) [i´ern]
a chemical element, atomic number 26, atomic weight 55.847. (See Appendix 6-1.) Iron is chiefly important to the human body because it is the main constituent of hemoglobin, cytochrome, and other components of respiratory enzyme systems. A constant although small intake of iron in food is needed to replace erythrocytes that are destroyed in the body processes. Most iron reaches the body in food, where it occurs naturally in the form of iron compounds. These are converted for use in the body by the action of the hydrochloric acid produced in the stomach. This acid separates the iron from the food and combines with it in a form that is readily assimilable by the body. Vitamin C enhances absorption of iron, and alkalis hamper absorption.
Iron Deficiencies. The amount of new iron needed every day by the adult body is about 18 mg. A child needs more in proportion to weight. Although these amounts are very small, iron deficiencies may cause serious disorders. Three stages of iron deficiency are distinguished: iron depletion or prelatent iron deficiency, in which bodily stores are mildly depleted but no change in hematocrit or serum iron levels is detectable; latent iron deficiency, in which the serum iron level has dropped but the hematocrit is unchanged and there is no anemia; and iron deficiency anemia, a serious condition characterized by low to absent iron stores, low hematocrit, and other blood abnormalities. A great loss of blood, such as may result from bleeding ulcers, hemorrhoids, or injury, is the most common cause of a deficiency of iron. Women who lose much blood in menstruation may have to supplement their diet with iron-rich food. Iron deficiency sometimes occurs in pregnancy as a result of increased demands on the mother's blood. It may also occur in infants, since milk contains little iron. Although babies are born with an extra supply of hemoglobin, by the age of 2 or 3 months they need iron-rich food to supplement milk.

Iron preparations, such as ferrous sulfate, may be necessary in the treatment of iron deficiency anemia; they should be administered after meals, never on an empty stomach. The patient should be warned that the drugs cause stools to turn dark green or black. Overdosage may cause severe systemic reactions.

An acute iron deficiency may warrant parenteral administration of an iron supplement. Hypersensitivity to iron supplements often occurs in patients with other known allergies. In other patients the parenteral administration of iron can cause vomiting, chills, fever, headache, joint pain, and urticaria.
Food Sources of Iron. Liver is the richest source of iron; 200 g (6 ounces) of liver contains a whole day's supply for an adult. Other iron-rich foods include lean meat, oysters, kidney beans, whole wheat bread, kale, spinach, egg yolk, turnip greens, beet greens, carrots, apricots, and raisins.
Iron metabolism. Uptake of heme iron or ferrous iron occurs in the intestine. From the intestine, iron is transported on transferrin to the liver or the bone marrow. Transferrin binds to red blood precursors in the bone marrow and delivers iron for incorporation into hemoglobin. Red blood cells in the circulation contain 60 percent to 80 percent of body iron. Old red blood cels are destroyed in the spleen. The iron is bound to transferrin for recirculation. Approximately 20 percent to 30 percent of iron is stored in the form of hemosiderin in the spleen, liver, and bone marrow. The remaining iron is in the respiratory enzymes of somatic cells. Iron is lost by desquamation of skin and intestinal cells. From Damjanov, 2000.
iron 59 a radioisotope of iron having a half-life of 44.5 days; used in ferrokinetics tests to determine the rate at which iron is cleared from the plasma and incorporated in red blood cells. Symbol 59Fe.
iron dextran a complex of iron and dextran of low molecular weight; administered intravenously or intramuscularly as a hematinic.
iron poisoning poisoning from ingestion of excessive iron or iron-containing compounds, such as in children who eat iron supplement tablets like candy; symptoms include ulceration of the gastrointestinal tract, vomiting, vasodilation with shock, metabolic acidosis, liver injury, and coagulation disturbances.
iron storage disease hemochromatosis.
iron sucrose a complex of ferric hydroxide, Fe(OH)3, in sucrose; used intravenously to treat iron deficiency anemia in hemodialysis patients receiving supplemental erythropoietin therapy.

i·ron (Fe),

(ī'ŏrn, ī'rŏn),
A metallic element, atomic no. 26, atomic wt. 55.847, which occurs in the heme of hemoglobin, myoglobin, transferrin, ferritin, and iron-containing porphyrins, and is an essential component of enzymes such as catalase, peroxidase, and the various cytochromes; its salts are used medicinally. For individual salts not listed below, see ferric and ferrous entries.
[A.S. iren]


(Fe) (i´ern) chemical element, at. no. 26; it is an essential constituent of hemoglobin, cytochrome, and other components of respiratory enzyme systems. Depletion of iron stores may result in iron-deficiency anemia, and various salts or complexes of iron are used as hematinics, including i. dextran, i.-polysaccharide, i. sorbitex, and i. sucrose.

iron (Fe)

Etymology: AS, iren
a common metallic element essential for the synthesis of hemoglobin. Its atomic number is 26; its atomic mass is 55.85. Iron salts and complexes, including ferrocholinate, ferrous fumarate, ferrous gluconate, ferrous sulfate, and iron dextran, are used to treat iron-deficiency anemias.


Iron-binding capacity, total iron-binding capacity, TIBC A metallic element–atomic number 26; atomic weight 55.8 essential to life, bound to Hb and responsible for O2 transportation–total iron refers to the amount of iron actually present in serum; iron and TIBC are performed on autoanalyzers Ref range Iron, 40-180 µg/dL; TIBC, 250-390 µg/dL. See Total iron-binding capacity, Transferrin.


A metallic element, atomic no. 26, atomic wt. 55.847, which occurs in the heme of hemoglobin, myoglobin, transferrin, ferritin, and iron-containing porphyrins; an essential component of enzymes such as catalase, peroxidase, and the various cytochromes; salts used medicinally.
[M.E. iren, fr. O.E. īren]


An element essential for the formation of HAEMOGLOBIN. Lack of iron, or excessive loss leads to IRON-DEFICIENCY ANAEMIA. Iron is provided in a variety of chemical forms for the treatment of anaemia and is usually taken by mouth. In urgent cases, or if oral therapy fails, iron can be given by injection.


an essential micronutrient; present in the body in the oxygen transport proteins, haemoglobin (60-70% of total iron) and myoglobin (10% of total iron). Small amounts are present in the plasma, carried by the protein transferrin, and it is stored (as ferritin) in liver, spleen and bone marrow. A small component (around 2%) is used in metabolic systems (cytochrome C, in mitochondria). Elite and recreational athletes undertaking hard training have a higher requirement and turnover of iron than less active people and quickly deplete iron stores which if untreated can lead to iron deficiency anaemia, severely impairing aerobic performance.


; Fe metallic element, found in haemoglobin, myoglobin, transferrin, ferritin and iron-containing porphyrins; essential component of peroxidase and cytochromes; deficiency causes anaemia


n an essential mineral and element (Fe) found in leafy greens, meat, beans, peas, blackstrap molasses, and enriched breads and cereals; used as a supplement to relieve conditions associated with dietary deficiency and to enhance athletic performance. Excessive iron supplementation may also increase risk of cardiovascular conditions.


A metallic element that occurs in heme of hemoglobin, myoglobin, transferrin, ferritin, and iron-containing porphyrins and is an essential component of enzymes; its salts are used medicinally.
[M.E. iren, fr. O.E. īren]

iron (Fe),

n a common metallic element essential for the synthesis of hemoglobin. Its atomic number is 26 and its atomic weight is 55.85. Normal blood levels range between 60 and 190 micrograms.


a chemical element, atomic number 26, atomic weight 55.847, symbol Fe. See Table 6. Iron is chiefly important to the animal body because it is the main constituent of hemoglobin, cytochrome, and other components of respiratory enzyme systems. A constant although small intake of iron in food is needed to replace erythrocytes that are destroyed in the body processes.

a radioisotope of iron having a half-life of 45 days; used in ferrokinetics tests to determine the rate at which iron is cleared from the plasma and incorporated in red cells. Symbol 59Fe.
iron binding
absorbed iron is rapidly and tightly bound to a specific transport protein, transferrin or siderophilin, from which it is discharged at iron receptor sites in the bone marrow.
iron dextran
an injectable form of iron used in the prevention of iron deficiency. See iron poisoning (below).
iron galactan
used as an injection vehicle for iron in young piglets.
iron nutritional deficiency
is most common in piglets raised on sows kept indoors under artificial conditions. Clinical signs are pallor, dyspnea, edema of the head and a secondary diarrhea.
organic iron poisoning
see iron poisoning (below).
iron overload
storage of excessive iron in body tissues such as occurs in human idiopathic hemochromatosis is not recorded in animals, but overload may occur as a result of excessive therapy.
iron poisoning
overdosing piglets with iron compounds by mouth causes diarrhea and death. Organic iron preparations, usually dextrans, injected in piglets can cause deaths acutely, within an hour or two of injection. At postmortem examination there is myonecrosis of skeletal muscle. Deaths have also occurred within a few minutes of intramuscular injection of organic iron preparations in horses. Sudden death due to massive liver damage also recorded in newborn foals dosed orally with ferrous fumarate with or without yeast in a paste. Asymmetry of the hindquarters in pigs is also recorded as a sequel of intramuscular injections of iron. See also asymmetric hind quarter syndrome. Bore water often contains significant levels of iron and when used for fish culture in dams may cause mortalities.
iron pool
a source of readily available iron for metabolic emergencies, probably located in the bone marrow.
iron storage disease
iron-sulfur proteins
polypeptides that contain iron-sulfur centers capable of Fe2S2 or Fe4S4 stoichiometry and with standard reduction potential between NAD+ and ubiquinone. Critical components of many electron transport chains, e.g. in oxidative phosphorylation and photosynthesis.
total iron-binding capacity
the serum iron plus the unbound iron-binding capacity of the serum.
iron turnover
see iron turnover.
unbound iron-binding capacity
that portion of the plasma transferrin molecule that is not bound to Fe3+.
iron-yeast paste
highly hepatoxic in some newborn foals when fed as a dietary supplement.

Patient discussion about iron

Q. Why do I need an iron supplement? I am a 22 year old woman and my doctor told me that I need an iron supplement. Why?

A. Here is a movie about iron deficiency:

Q. What is the recommended intake for iron? I had a blood test recently which detected I have iron deficiency. I wanted to know what is the recommended intake for iron and which foods are rich with iron?

A. Adult males need to consume about 8 mg of iron per day and females (not pregnant) need to consume about 18 mg of iron per day. There are two forms of dietary iron: heme and nonheme. Heme iron is derived from hemoglobin, the protein in red blood cells that delivers oxygen to cells. Heme iron is found in animal foods that originally contained hemoglobin, such as red meats, fish, and poultry. Iron in plant foods such as lentils and beans is arranged in a chemical structure called nonheme.

Q. Why do pregnant women need more iron? During my pregnancy my Doctor keeps on telling me I need to take an iron supplement. I eat healthy and eat meat, isn't that enough?

A. How much iron you need during pregnancy depends a lot on how much you already have stored in your bone marrow, as well as how much you get daily in your diet. If you are a meat eater, you will need less iron than a non meat eater however you will still need an iron supplement since during pregnancy you need to consume a great amount of iron that is impossible to consume from food alone. Consult with your Doctor and tell him to run you a blood test. If he sees you have enough iron he might not recommend an iron supplement and will be satisfied with only a Prenatal vitamin, which also contains iron but less.

More discussions about iron
References in classic literature ?
This done, he went on to the pavement to make trial of the bow; thrice did he tug at it, trying with all his might to draw the string, and thrice he had to leave off, though he had hoped to string the bow and shoot through the iron.
Queen Penelope," answered Eurymachus, "we do not suppose that this man will take you away with him; it is impossible; but we are afraid lest some of the baser sort, men or women among the Achaeans, should go gossiping about and say, 'These suitors are a feeble folk; they are paying court to the wife of a brave man whose bow not one of them was able to string, and yet a beggarly tramp who came to the house strung it at once and sent an arrow through the iron.
On the second day Iron Hans equipped him as a white knight, and gave him a white horse.
It is a bare office, with bare windows, looking on the iron view below.
She darted from the bed to fling herself at the feet of the king's procurator, but her leg was fast in the heavy block of oak and iron, and she sank down upon the boot, more crushed than a bee with a lump of lead on its wing.
Men danced about outside, thrusting in with iron bars and trying to separate them.
Picking the lock of the iron door was out of the question, from the exposed nature of the situation which that mysterious iron barrier occupied.
But it were ridiculous to assert that the Iron Heel was a necessary stepping- stone.
Meantime the giant continued to raise his iron mallet high in the air and to strike the path terrific blows that echoed through the mountains like the roar of a cannon.
This valuable metal possesses the whiteness of silver, the indestructibility of gold, the tenacity of iron, the fusibility of copper, the lightness of glass.
She dropped her iron on the shirtwaist, clutched at the board, fumbled it, caved in at the knees and hips, and like a half-empty sack collapsed on the floor, her long shriek rising in the pent room to the acrid smell of scorching cloth.
When he had issued his instructions relative to every other part of the building, and the mob were dispersed from end to end, and busy at their work, he took a bundle of keys from a kind of cupboard in the wall, and going by a kind of passage near the chapel (it joined the governors house, and was then on fire), betook himself to the condemned cells, which were a series of small, strong, dismal rooms, opening on a low gallery, guarded, at the end at which he entered, by a strong iron wicket, and at its opposite extremity by two doors and a thick grate.